Two free point charges +q and +4q are a distance L apart. A third charge is placed so that the entire system is in equilibrium. Find the location, magnitude and sign of the third charge.

What happens in a global convection cell

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz. what wavelength is produced?

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?